| Message ID | 20180330221636.32512-1-longli@linuxonhyperv.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] cifs: smbd: avoid reconnect lockup | expand |
Looks good to me (both patches) Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> On Sat, Mar 31, 2018 at 8:16 AM, Long Li <longli@linuxonhyperv.com> wrote: > From: Long Li <longli@microsoft.com> > > During transport reconnect, other processes may have registered memory > and blocked on transport. This creates a deadlock situation because the > transport resources can't be freed, and reconnect is blocked. > > Fix this by returning to upper layer on timeout. Before returning, > transport status is set to reconnecting so other processes will release > memory registration resources. > > Upper layer will retry the reconnect. This is not in fast I/O path so > setting the timeout to 5 seconds. > > Signed-off-by: Long Li <longli@microsoft.com> > --- > fs/cifs/smbdirect.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c > index 5aa0b54..3f7883e 100644 > --- a/fs/cifs/smbdirect.c > +++ b/fs/cifs/smbdirect.c > @@ -1498,8 +1498,8 @@ int smbd_reconnect(struct TCP_Server_Info *server) > log_rdma_event(INFO, "reconnecting rdma session\n"); > > if (!server->smbd_conn) { > - log_rdma_event(ERR, "rdma session already destroyed\n"); > - return -EINVAL; > + log_rdma_event(INFO, "rdma session already destroyed\n"); > + goto create_conn; > } > > /* > @@ -1512,15 +1512,19 @@ int smbd_reconnect(struct TCP_Server_Info *server) > } > > /* wait until the transport is destroyed */ > - wait_event(server->smbd_conn->wait_destroy, > - server->smbd_conn->transport_status == SMBD_DESTROYED); > + if (!wait_event_timeout(server->smbd_conn->wait_destroy, > + server->smbd_conn->transport_status == SMBD_DESTROYED, 5*HZ)) > + return -EAGAIN; > > destroy_workqueue(server->smbd_conn->workqueue); > kfree(server->smbd_conn); > > +create_conn: > log_rdma_event(INFO, "creating rdma session\n"); > server->smbd_conn = smbd_get_connection( > server, (struct sockaddr *) &server->dstaddr); > + log_rdma_event(INFO, "created rdma session info=%p\n", > + server->smbd_conn); > > return server->smbd_conn ? 0 : -ENOENT; > } > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
merged into cifs-2.6.git for-next added cc:stable On Fri, Mar 30, 2018 at 5:23 PM, ronnie sahlberg <ronniesahlberg@gmail.com> wrote: > Looks good to me (both patches) > > Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> > > On Sat, Mar 31, 2018 at 8:16 AM, Long Li <longli@linuxonhyperv.com> wrote: >> From: Long Li <longli@microsoft.com> >> >> During transport reconnect, other processes may have registered memory >> and blocked on transport. This creates a deadlock situation because the >> transport resources can't be freed, and reconnect is blocked. >> >> Fix this by returning to upper layer on timeout. Before returning, >> transport status is set to reconnecting so other processes will release >> memory registration resources. >> >> Upper layer will retry the reconnect. This is not in fast I/O path so >> setting the timeout to 5 seconds. >> >> Signed-off-by: Long Li <longli@microsoft.com> >> --- >> fs/cifs/smbdirect.c | 12 ++++++++---- >> 1 file changed, 8 insertions(+), 4 deletions(-) >> >> diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c >> index 5aa0b54..3f7883e 100644 >> --- a/fs/cifs/smbdirect.c >> +++ b/fs/cifs/smbdirect.c >> @@ -1498,8 +1498,8 @@ int smbd_reconnect(struct TCP_Server_Info *server) >> log_rdma_event(INFO, "reconnecting rdma session\n"); >> >> if (!server->smbd_conn) { >> - log_rdma_event(ERR, "rdma session already destroyed\n"); >> - return -EINVAL; >> + log_rdma_event(INFO, "rdma session already destroyed\n"); >> + goto create_conn; >> } >> >> /* >> @@ -1512,15 +1512,19 @@ int smbd_reconnect(struct TCP_Server_Info *server) >> } >> >> /* wait until the transport is destroyed */ >> - wait_event(server->smbd_conn->wait_destroy, >> - server->smbd_conn->transport_status == SMBD_DESTROYED); >> + if (!wait_event_timeout(server->smbd_conn->wait_destroy, >> + server->smbd_conn->transport_status == SMBD_DESTROYED, 5*HZ)) >> + return -EAGAIN; >> >> destroy_workqueue(server->smbd_conn->workqueue); >> kfree(server->smbd_conn); >> >> +create_conn: >> log_rdma_event(INFO, "creating rdma session\n"); >> server->smbd_conn = smbd_get_connection( >> server, (struct sockaddr *) &server->dstaddr); >> + log_rdma_event(INFO, "created rdma session info=%p\n", >> + server->smbd_conn); >> >> return server->smbd_conn ? 0 : -ENOENT; >> } >> -- >> 2.7.4 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-cifs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index 5aa0b54..3f7883e 100644 --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -1498,8 +1498,8 @@ int smbd_reconnect(struct TCP_Server_Info *server) log_rdma_event(INFO, "reconnecting rdma session\n"); if (!server->smbd_conn) { - log_rdma_event(ERR, "rdma session already destroyed\n"); - return -EINVAL; + log_rdma_event(INFO, "rdma session already destroyed\n"); + goto create_conn; } /* @@ -1512,15 +1512,19 @@ int smbd_reconnect(struct TCP_Server_Info *server) } /* wait until the transport is destroyed */ - wait_event(server->smbd_conn->wait_destroy, - server->smbd_conn->transport_status == SMBD_DESTROYED); + if (!wait_event_timeout(server->smbd_conn->wait_destroy, + server->smbd_conn->transport_status == SMBD_DESTROYED, 5*HZ)) + return -EAGAIN; destroy_workqueue(server->smbd_conn->workqueue); kfree(server->smbd_conn); +create_conn: log_rdma_event(INFO, "creating rdma session\n"); server->smbd_conn = smbd_get_connection( server, (struct sockaddr *) &server->dstaddr); + log_rdma_event(INFO, "created rdma session info=%p\n", + server->smbd_conn); return server->smbd_conn ? 0 : -ENOENT; }